This invention pertains generally to mosquito control and in particular to a nonpoisonous mosquito larvae and pupae control.
A common approach to mosquito control is to prevent the emergence of the adult from its aquatic breeding site through the application of a water-immiscible, organic chemical which forms a film on the water. It is necessary for these film-forming chemicals and the surface films which they form to have certain physicochemical properties to ensure not only effectiveness against aquatic forms of mosquito, but also ease of application and persistence. The chemicals must be nonionic, nonvolatile, and water immiscible liquids. Furthermore, the chemicals and the resulting films must have a low freezing point, be commercially available at a reasonable cost, and be nontoxic and be noncorrosive. It is also necessary for the surface film to be fluid with rapid and spontaneous spreading and with high respreading potential.
Unfortunately, the presently used compounds fail to have one or more of these properties. Petroleum-based oils have, in general, the disadvantages of fouling the shore areas, killing other marine life and vegetation, and extra cost due to a large usage requirement. The nonvolatile hydrocarbon component of these films containing only alkanes and cycloalkanes are slow in their impact on larvae. The more rapid toxic effects are obtained from volatile aromatics and other toxic compounds contained in these films which are drawn into the larvae breathing trachae during respiration. However, these compounds have poor resistance because of their volatility and often are toxic to too many other aquatic creatures.